1. Field of the Invention
The present invention relates to methods and apparatus for processing digital image signals, and, in particular, to decoders for decoding digital image data.
2. Description of the Related Art
Conventional systems for playing video in a PC environment are limited, in part, by the processing capabilities of the PC processors. These limitations include low video frame rates and small video window sizes for display of video images. Such limitations result in low video quality. As a result, some conventional systems for playing video in a PC environment require additional hardware that is designed to process video data at the rates needed to provide acceptable video quality.
It is, therefore, desirable to provide a playback video system for displaying high-quality, full-motion digital video images on a graphics display monitor in a personal computer (PC) environment that does not require any additional hardware. Such a playback video system is preferably capable of performing decoding and display functions to support playback mode. In playback mode, the playback video system accesses encoded video data from a mass storage device, decodes the data, and displays the decoded data on a display monitor.
It is also desirable to provide a compression video system for generating the encoded video data that will be decoded and displayed by the playback video system. Such a compression video system is preferably capable of performing capture, encoding, decoding, and display functions to support both a compression mode and the playback mode. In compression mode, the compression video system captures and encodes video images generated by a video generator, such as a video camera, VCR, or laser disc player. The encoded video data may then be stored to a mass storage device., such as a hard drive or, ultimately, a CD-ROM. At the same time, the encoded video data may also be decoded and displayed on a display monitor to monitor the compression-mode processing.
It is accordingly an object of this invention to overcome the disadvantages and drawbacks of the known art and to provide a decoder for a playback video system for displaying high-quality, full-motion video images in a PC environment.
It is a particular object of the present invention to provide a decoder for a playback video system for displaying video images under a multi-media operating system running on a personal computer with a general-purpose processor.
Further objects and advantages of this invention will become apparent from the detailed description of a preferred embodiment which follows.